Karl F. Renk received a diploma degree (1962) and a Ph.D. (1966) in physics from the Universität Freiburg, Germany. He worked as a Senior Research Physicist at the University Reading, Great Britain (1966/67) and as Wissenschaftlicher Assistant at the Technische Universität München (1967-72). From 1972 to 2006, he was a Professor of Physics at the Universität Regensburg, Germany, and since 2006, Professor Emeritus. He had visiting appointments at the Research Center Jülich (1974), High-Field Magnet Laboratory of the Max-Planck Society, Grenoble (1976), University of California, Los Angeles (1980/81), Université Scientific et Médicale de Grenoble (1985/86), and at the University of Canterbury, Christchurch, New Zealand (1992) as a New Zealand Erskine Fellow. Professor Renk is a fellow of the American Physical Society, the Deutsche Physikalische Gesellschaft, and the Gesellschaft Deutscher Naturforscher und Ärzte. He developed the first Fabry-Perot interferometer for the far infrared (1962), later far infrared lasers and, finally, millimeter wave devices based on semiconductor superlattices and applied the techniques together with optical laser techniques to study dynamical processes of low-energy excitations in solids. The work is documented in about 250 scientific publications.